Pressure release device



Patented i659 iiiNi'iE. STATES PATENT OFFICE PRESSURE RELEASE DEVICEJohn H. Stroop, New York, N. Y., assigner to Specialties DevelopmentCorporation, Bloomiielol, N. J., a corporation of New Jersey ApplicationDecember 30, 1944, Serial No. 570,713

8 Claims. (Cl. 251-134),

This invention relates to improvements in pressure medium releasedevices used, for example, in connection with fire extinguishers whereina re extinguishing medium is stored under pressure and a valve mechanismis provided for effecting release of the medium.

More specifically, the invention is directed to improved valve mechanismand valve operating mechanism particularly adapted for portable fireextinguishers.

In small light weight portable extinguishers of the trigger operatedtype, the handle is substantially parallel with the vertical axis of thecontainer, and the trigger for actuating the valve opening means isconveniently located for ready operation by one nger of the operator inthe form of a pistol grip. While this type of mechanism has been foundvery satisfactory for small extinguishers, the same type handle andtrigger mechanism are not readily adaptable to, or convenient for usewith, larger and heavier portable extinguishers. Accordingly heavyportable extinguishers have heretofore been provided with a hand wheelor other valve opening mechanism not as readily operable as a triggermechanism.

An other object of the present invention resides in the provision oftrigger mechanism which requires comparatively little eiort to operatein opening a valve.

Another object of the invention resides in the provision of means foramplifying the force applied to the trigger to eiiect cracking and fullopening of the valve.

Another object of the invention resides in the vprovision of means fortransmitting a valve opening force from linear to rotary and back tolinear motion.

Another object of the invention resides in the provision of convenientlyactuated means for latching the trigger mechanism in a position toretain the valve open.

Another object of the invention resides in the provision of a valve andvalve actuating trigger, each of which, is moved in paths substantiallyparallel with the vertical axis of the container.

A further object ci the invention resides in the provision of a heavyportable re extinguisher f with trigger mechanism of the foregoing typefor opening the valve of the extinguisher to discharge the fireextinguishing medium.

Other and further objects of the invention will be obvious upon anunderstanding of the illustrative embodiment about to be described, orwill Vbe indicated in the appended claims, and

various advantages not referred to herein will 2 occur to one skilled inthe art upon employment of the invention in practice.

A preferred embodiment of the invention has been chosen for purposes ofillustration and description and is shown in the accompanying drawing,forming a part of the speciiication, wherein:

Figure l is a vertical sectional view ofthe outlet portion of a fireextinguisher embodying the present invention;

Figure 2 is a sectional view taken substantially on line 2 2 of Figure1;

Figure 3 is a top plan view thereof, partly in section; and

Figure 4 is a right hand elevational view thereof.

Referring to the drawing in detail, a container I0 is provided for reextinguishing medium under pressure, such as carbon dioxide, forexample. This container is `provided with a reduced end forming a neckI2 which is threaded to receive a valve body I4.

A bore I6 is formed in the valve body I4 to provide a valve chamberaccommodating a valve member' 2l)I which is normally held on a valveseat 22 by means of a spring 24 aided by the pressure of the fluid inthe container acting on the underside of the valve member. The valvemember 20 has a valve stem 26, extending to the outside of the valvebody and provided with a shoulder 28 fitting within a valve stem packingchamber 30. Within this chamber the valve stem supports an annularpacking 32 intermediate the shoulder 28 and the outer end of thechamber. The packing 32 is circular in cross Section and is of the typeknown as a doughnut packing.

A carrying handle 34 is provided for the device Which extendssubstantially at right angles to the vertical axis of the container.This handle is in the form oi' a channel member extending over and aboutthe top of the valve body and secured thereto by means of screws 31 anda y hose attaching fitting 36 having a portion serving as a locking nut,the handle being provided with an aperture 35 on its forward end toaccommodate a portion of the tting 36 threaded into the valve body. Thehandle also has a notch or recess 39 cut therein to slip over a safetyplug 4I, and also has a pair of positioning bosses 38 which cooperatewith depressions in the valve body for positioning the handle thereon.The bosses receive the screws 31 whichare threadedly secured to valvebody (Figure 4). The handle also serves as a housing or casing for avalve opening mechanism for actuating the valve in a manner about to bedescribed. As will be seen from Figure 2 the sides of the handle whichencloses the valve opening mechanism are bent inwardly to form dependingflanges 33.

The valve opening mechanism comprises a trigger 40 slidable between theflanges 33 of the handle and carrying a low amplification roller 42 anda high amplification roller 44. These rollers are freely rotatable onhollow shafts 46 and 48, respectively, carried by the trigger 40, andare adapted to contact cam surfaces on a wedge shaped lever or triggerarm 50. The trigger arm is pivotally mounted on a pin 52 in the valvebody and has a finger 54 extending over the free, or outwardly extendingend of the valve stem 26, so that upon rotation of the arm about itspivot the finger 54 will engage the valve stem whereby to unseat thevalve in a manner to be described presently. It will be noted that thefinger 54 normally is spaced slightly from the valve stem to provide atolerance gap` A spring 56 is provided for holding the trigger andtrigger arm in operative relation. This spring is in the form of springwire having a loop 58 substantially midway of its free ends and inengagement with a shoulder 60 on the trigger arm 50. The strands of thewire pass from the loop about the pivot pin 52 on each side of the arm50, thence rearwardly a predetermined distance where they are bentdownwardly substantially at right angles and have their free ends hookedabout the hollow shaft 46 of the low amplification roller 42.

A removable locking pin 64 is provided to lock the parts of the triggermechanism in non-operative position to prevent accidental operation-andto discourage unauthorized operation thereof and consequent discharge ofthe fire extinguishing medium from the container. 'I'his pin has a loop68 and substantially parallel legs or prongs 1li. The handle 34 has apair of holes in at least one wall thereof, in registry with the hollowshafts 46 and 48 when the parts are in valve closed position. When it isdesired to lock the parts in non-operative or valve closed position, theprongs of the locking pin are inserted through the holes in the handleand into the hollow shafts 46 and 48. When the pin is in place, as justdescribed, there can be no movement of the trigger mechanism to open thevalve, as will be readily understood. Upon removal of the pin, thetrigger 40 is cocked into operating position by being urged upwardbetween and against the trigger arm 50 and valve body I4 by means of thespring 56 to condition the parts of the trigger mechanism for immediateoperation of the valve.

When force is applied to the trigger 40, by the finger of the operator,a slight movement thereof in a clockwise direction, as viewed in Figure1, brings the high amplification roller 44 into engagement with highamplification cam surface 12 of the lever or trigger arm 50 causing thearm to rotate on its pivot 52 to bring its finger 54 into engagementwith the end of the valve stem 26. Further upward movement of thetrigger 40 in substantial parallel alignment with the vertical axis ofthe container will carry the high amplification roller 44 along the faceof the arm 50 to cause further rotation of the trigger arm 50 wherebythe valve will be cracked or unseated. Continued movement of the trigger40 will cause the low amplification roller 42 to engage lowamplification surface 14 of the trigger arm 50 whereby further rotationof the arm 5I is effected to effect complete opening of the valveagainst the action of the spring 24 to permit the 4 fire extinguishingmedium to be discharged fiom the container through the hose outlet 36.

The action of trigger 40 is a combination of a wedge being pressedbetween trigger arm 59 and the adJacent portion of valve body I4, and aleverV with fulcrum at the point where the surface of idler 42 contactsthe surface of the valve body I4, both actions tending to-rotate thetrigger arm 50 about its pivot 52.

Upon release of pressure from the trigger 40 the valve spring 24 willreturn the valve 20 to its seat 22 and cut off the flow of the fireextinguishing medium. Should it be desired to continue the discharge ofthe medium, the trigger may be rotated in a counterclockwise directionwhereby to bring a notch 16 formed on the trigger into engagement with alip or projection 18 on the handle 3D, whereby the trigger mechanism maybe latched in position to retain the valve unseated.

It will be seen from the foregoing that the present invention provides atrigger operated. fiie extinguisher particularly well adapted for heavyportable extinguishers. The handle I4 extends substantially at rightangles to the vertical axis of the container, the trigger 40 ispositioned within easy reach of the index finger of the operator, andall of the operating parts with the exception of the operating end ofthe trigger are protected by the handle.

The force applied to the trigger provides a two-stage amplification tocrack the valve and a low stage amplification immediately followingproviding a full opening of the valve. In practice it has been foundthat the initial resistance force of the valve is from 100 to 300pounds, while the last stage offers only the stem end area pressure ofabout 10 pounds. The amplification provided by the mechanism of thepresent invention is ample to overcome this resistance without any undueeffort on the part of the operator. The high amplification is effectedby the trigger 40 acting on the trigger arm 80 through the wedge androller combination described; the applied force acting outside of thepivotal point of resistance causing rotation of the trfgger as a leverhaving a ratio of three to one. This ratio is transmitted through roller44 to the cam surface 12 with at least a two and one half to one ratio.The first ratio of the trigger arm being a minimum of three to one, theultimate ratios are between twenty and twenty-five to one, making thetrigger force requirements, for any normal operation, five to tenpounds, the most excessive required pull being about fifteen pounds.

In the mechanism of the present invention the high amplification needonly be applied to crack the valve five to ten thousandths of an inch,inasmuch as when the resistance drops the low amplification rollerimmediately contacts the low amplification surface of the trigger armand throws the valve completely open.

As various changes may be made in the form, construction and arrangementof the parts herein. without departing from the spirit and scope of theinvention and without sacrificing any of its advantages, it is to beunderstood that all matter herein is to be interpreted as illustrativeand not in any limiting sense.

It is also to be understood that the following' varm for engaging saidstem and having a second `arm provided with a cam surface adjacent saidtrack surface, va trigger constructed and arranged for movement in asubstantially longitudinal direction with respect to said second leverarm, and means on said` trigger cooperating with said cam surface andsaid track surface upon linear movement of said trigger to effectpivotal movement of said lever to cause said stem to unseat said valvemember.

2. A release device for iluid under pressure comprising a valve bodyhaving a track surface at one side thereof, a valve seat in said valvebody, a valve member for said seat, a stem for moving said valve memberoi its seat having an end extending outwardly of said valve body, alever pivotally mounted on said valve body having an arm for engagingsaid stem and having a second arm provided with a cam surface adiacentsaid track surface, a trigger constructed and arranged for movement in asubstantially longitudinal direction wih respect to said second leverarm, and a pair of rollers on said trigger each cooperating with saidcam surface and at least one of said rollers cooperating with said tracksurface upon linear movement of said trigger to etfect pivotal movementof said lever to cause said stem fo unseat said valve member.

3. A release device for ii-uid under pressure comprising a valve bodyhaving a track surface at one side thereof, a valve seat in said valvebody, a valve member Vfor said seat, a stem for moving said valve memberoff its seat having an end extending outwardly of said valve body, alever pivotally mounted on said valve body having an arm for engagingsaid stern and having a second arm adjacent said track surface providedwith a cam surface having an upper and lower contour, a triggerconstructed and arranged for movement in a substantially longitudinaldirection with respect to said second lever arm', and a pair of rollerson said trigger, one of said rollers cooperating with said upper contourand said track surface and the other of said rollers cooperating withsaid lower contour upon linear movement of said trigger to effectpivotal movement of said lever to cause said stem to unseat said valvemember.

4. A release device for fluid under pressure comprising a valve bodyhaving a track surface at one side thereof, a valve seat in said valvebody, a valve member for said seat, a stem for moving said valve memberoff its seat having an end extending outwardly of said valve body, alever pivotally mounted on said valve body having an arm for engagingsaid stem and having a second arm provided with a cam surface adjacentsaid track surface, a latching projection on said valve portion, atrigger constructed and arranged for movement in a substantiallylongitudinal direction with respect to said second lever arm, and meanson said trigger cooperating with said -cam surface and said tracksurface upon linear movement of said trigger to effect `pivotal movementof said lever to cause said stem to unseat said valve member, saidtrigger having a shoulder adapted to engage said proasocu jection tolatch said trigger and lever in valve member u'nseating position.

5. A release device for fluid under pressure vcomprising a valve bodyhaving a track surface at one side thereof, a valve seat in said valvebody, a valve member for said seat, a stem for moving said valve memberoif its seat having an end extending outwardly of said valve body, alever pivotally mounted on said valve body having an arm forv engagingsaid stem and having a second arm provided with a cam surface adjacentsaid` track surface, a trigger constructed and arranged for movement ina substantially longitudinal direction with respect to said second leverarm, means on said trigger cooperating with said cam surface and saidtrack surface upon linear movement of said trigger to effect pivotalmovement of said lever to cause said stem to unseat said valve member,and resilient means connecting said lever and trigger.

6. A release device for fluid under pressure comprising a valve bodyhaving a track surface at one side thereof, a handle on said valve bodyhaving -apertures therein, a valve' seat in said valve body, a valvemember for said seat, a stem for moving said valve member off its seathaving an end extending outwardly of said valve body, a lever pivotallymounted on said valve body having an arm for engaging said stem andhaving a second arm provided with a cam surface adjacent said tracksurface, a trigger constructed and arranged for movement in asubstantially longitudinal direction with respect to said second leverarm, rollers on said trigger cooperating with said cam surface and saidtrack surface upon linear movement of said trigger to effect pivotalmovement of said lever to cause said stem to unseat said valve member,hollow shafts for mounting said rollers on said trigger, and a lockingmember having legs extending through said apertures and said hollowshafts to lock said trigger.

7. A device for releasing fluid under pressure comprising a valve body,a valve seat in said valve body, a valvemember for said valve seat, astem for moving said valve member oil its seat having an end extendingoutwardly of said valve body, a lever pivotally mounted on said valvebody having an arm for engaging said stem, a latching projection on saidvalve body, and a trigger carried by said lever and constructed andarranged to effect pivotal movement of said lever to cause said arm toengage said stem and move the same to unseat said valve member, saidtrigger having a shoulder adapted to engage said projection to latchsaid trigger and lever in valve member unseating position.

8. A device for releasing uid under pressure comprising a valve body, ahandle on said valve body having a latching projection, a valve seat insaid valve body, a valve member for said valve seat, a stem for movingsaid valve member oil.' its seat having an end extending outwardly ofsaid valve body, a lever pivotally mounted on said valve body having anarm for engaging said stem, a latching projection on said valve body,and a trigger carried by said lever constructed and arranged to eiectpivotal movement of said lever to cause said arm to engage said stem andmove the same to unseat said valve member, said trigger having ashoulder adapted to engage said projection to latch said trigger andlever in valve member unseating position.

JOHN H. STROOP.

(References on following page) REFERENCES CITED Number The followingreferences are of record in the 1 le of thls patent: 119071683 UNITEDSTATES PATENTS 5 2,375,615

Number Name Date Re. 19,087 Minor Feb. 20, 1934 N b Re.22,o45 TowartMar. 3, 1942 ugf 161,768 Doherty Apr. 6, 1875 10 Name Date Whitney Dec.20, 1910 McFarlan Dec. 15, 1925 Tews May 9, 1933 Boal May 8, 1945FOREIGN PATENTS Country I Date Great Britain of 1928

